Data storage tape systems have been used for decades in the computer, audio, and video fields. The data storage tape system includes a tape drive and one or more data storage tape cartridges. During use, storage tape is driven along a tape path between a first tape reel assembly within the cartridge and a second tape reel assembly within the drive. Regardless of exact form, the data storage tape system continues to be a popular format for recording large volumes of information for subsequent retrieval and use.
With the above in mind, a data storage tape cartridge generally consists of an outer shell or housing maintaining at least one tape reel assembly and a length of magnetic storage tape. The storage tape is wrapped about a hub of the tape reel assembly and is driven through a defined path by a driving system. The housing normally includes a separate cover and a separate base. Together, the cover and the base form an opening (or window) at a forward portion of the housing facilitating access to the storage tape by a read/write head upon insertion of the data storage tape cartridge into the tape drive. The interaction between the storage tape and the head can occur within the housing (i.e., a mid-tape load design) or exterior to the housing (i.e., a helical drive design). Where the head/storage tape interaction is exterior to the housing, the data storage tape cartridge normally includes a single tape real assembly employing a leader block or similar device. Alternately, where the head/storage tape interaction is within the housing, a dual tape reel cartridge configuration is typically employed.
Regardless of the number of tape reel assemblies associated with a particular data storage tape cartridge, the tape reel assembly (also known as a spool) generally includes a hub and one or more reel flanges. In general, the hub includes a core that defines a tape winding surface. The reel flanges are optional, and if employed, are disposed at opposite ends of the hub. To this end, the flanges have a spacing slightly wider than a width of the storage tape to facilitate winding of the storage tape onto, and off of, the tape winding surface.
With this in mind, the spacing between the flanges may permit scatter winds to form. As a point of reference, the winding of the storage tape is often characterized by high linear tape speeds. The high speed of the storage tape as it enters the spool entrains air between successive windings of the storage tape, creating winding forces that can result in an axial movement of the storage tape relative to the hub. The axial movement of the storage tape, in combination with the slightly wider spacing of the flanges (as compared to the tape width), results in an occasional edge of the storage tape being staggered at a different elevation than other edges of the wound storage tape. Scatter winds are thus edges of wound storage tape that are not uniformly aligned with the other edges of the wound storage tape.
Prior art data storage tape cartridges are normally provided with brake buttons that engage with the tape reel assembly to prevent the tape reel assembly from rotating as the cartridge is handled. In this regard, the brake button includes engagement teeth configured to mate with a corresponding brake surface formed within (or by) the hub of the tape reel assembly. When the data storage tape cartridge is not engaged with the tape drive (i.e., when the cartridge is being handled), the teeth of the brake button are engaged with the brake surface of the tape reel assembly to prevent rotation of the tape reel assembly. That is to say, the prior art data storage tape cartridges are designed to prevent the rotation of the tape reel assembly when the cartridge is disengaged from the tape drive such that the storage tape does not inadvertently unravel from the tape reel assembly.
While the above-described brake button design does address unintended unraveling of the storage tape, it fails to account for the possible axial displacement of the tape reel assembly within the cartridge housing. In particular, a spool filled with data storage tape has a mass that can achieve a high momentum when the cartridge is handled, for example when the cartridge is accidentally dropped or roughly jostled. To this end, although the tape reel assembly is impeded from rotation due to the engagement of the brake button with the brake surface of the tape reel assembly, the tape reel assembly (and in particular the tape reel flanges) can be rattled inside the cartridge such that the flanges contact and deform the scatter winds of the storage tape. Contact of the flanges with the scatter winds has the potential to crush the data storage tape and damage the “tracks” of information stored along the tape. Consequently, damaged edges of the storage tape can cause storage tape tracking problems and reduce the life cycle of the storage tape.
Scatter winds resulting from the winding and unwinding of storage tape onto tape spools is a common characteristic of data storage tape cartridges. With increasing speeds of reading/writing information, and advanced magnetic tape technology, the accurate and consistent access to information stored on the storage tape is directly related to the condition of the storage tape. To this end, damage to the scatter winds of the storage tape present on a packed spool will reduce the life cycle of the storage tape. Therefore, a need exists for a data storage tape cartridge that minimizes the potential damage to the scatter winds.